p. 338: There is no such thing as a “tipping point” (or even a “precautionary principle”) in science. The precautionary principle is proposed for the conduct of human affairs. No-one seriously proposes it as a scientific principle. (If it was a scientific principle

there thing

would be no as a “tipping

need to argue for point” in science,

its use — it would just happen). There is such but the more technical name is “catastrophe”.

a n

accessible account is given in the book Catastrophe Theory by V. I.

rnold (Springer-

Verlag, 1984, 1986). Since not all things that are catastrophes in the mathematical sense are catastrophic in the human sense, the use of a less ambiguous term such as “tipping point” seems desirable for public communication.

65.

p. 346–347, figures 38, 39, 40: whereas monthly averages do not.

nnual averages show sea surface temperature rises and in the caption of figure 40: The three diagrams

show that the data can easily be manipulated to create a desired outcome.

ctually no.

In particular the linear trend will be almost the same in each case, with small differ- ences coming from a few months at the end. Fitting a trend to monthly, 5-monthly or 12-monthly averages involves (apart from the ends and some rounding of times) the same sums over the same months, whether or not one deals with averages. Using 5-month av- erages just means that each month gets added in 5 times (and divided by 5). From the basic laws of arithmetic, the sum of a set of numbers does not depend on the order in which they are added. So why do the graphs seem to have different trends: because they are plotted on different scales. Each actually shows about 0.7◦C increase over the 40-odd years. This same scam was used by Michael Crichton in State of Fear comparing US and

global data — see section 3.2 of Twisted.

66. p. 350: The El Nin˜o most commonly occurs in late Decembe , lasts for a month or so . . . compared to p. 352 El Nin˜o lasts for 1 to 2 years.

67.

P

351:

In

India

in

the

1920s

...

alker

used

weather

stations

at

Darwin

(

ustralia)

and

ahiti, which had 100 years of records and showed a see-saw correlation (hence the Southern Oscillation). Wrong. There were not 100 years of records from Darwin be- cause Darwin was not settled until 1869 (initially called Palmerston). More specifically, Walker used a large number of records, and even by the early 1930s, few of these had more than 50 years of data — [DK].

68.

p. 365: Clouds are not factored into climate models. Untrue. See for example sections 12 and 13 of CSIRO Division of tmospheric Research Technical Paper no. 26, available on-

line from the CSIRO Marine and

tmospheric Research website.

lso many textbooks.

69. p. 366: assertion of the 0.5◦C climate sensitivity with no citation and contradicting other values given by Plimer [items 104, 124] — [TL].